bus/connection.c

   1 /* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
   2 /* connection.c  Client connections
   3  *
   4  * Copyright (C) 2003  Red Hat, Inc.
   5  *
   6  * Licensed under the Academic Free License version 2.1
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  21  *
  22  */
  23
  24 #include <config.h>
  25 #include "connection.h"
  26 #include "dispatch.h"
  27 #include "policy.h"
  28 #include "services.h"
  29 #include "utils.h"
  30 #include "signals.h"
  31 #include "expirelist.h"
  32 #include "selinux.h"
  33 #include "apparmor.h"
  34 #include <dbus/dbus-list.h>
  35 #include <dbus/dbus-hash.h>
  36 #include <dbus/dbus-timeout.h>
  37 #include <dbus/dbus-connection-internal.h>
  38 #include <dbus/dbus-internals.h>
  39
  40 /* Trim executed commands to this length; we want to keep logs readable */
  41 #define MAX_LOG_COMMAND_LEN 50
  42
  43 static void bus_connection_remove_transactions (DBusConnection *connection);
  44
  45 typedef struct
  46 {
  47   BusExpireItem expire_item;
  48
  49   DBusConnection *will_get_reply;
  50   DBusConnection *will_send_reply;
  51
  52   dbus_uint32_t reply_serial;
  53
  54 } BusPendingReply;
  55
  56 struct BusConnections
  57 {
  58   int refcount;
  59   DBusList *completed;  /**< List of all completed connections */
  60   int n_completed;      /**< Length of completed list */
  61   DBusList *incomplete; /**< List of all not-yet-active connections */
  62   int n_incomplete;     /**< Length of incomplete list */
  63   BusContext *context;
  64   DBusHashTable *completed_by_user; /**< Number of completed connections for each UID */
  65   DBusTimeout *expire_timeout; /**< Timeout for expiring incomplete connections. */
  66   int stamp;                   /**< Incrementing number */
  67   BusExpireList *pending_replies; /**< List of pending replies */
  68
  69   /** List of all monitoring connections, a subset of completed.
  70    * Each member is a #DBusConnection. */
  71   DBusList *monitors;
  72   BusMatchmaker *monitor_matchmaker;
  73
  74 #ifdef DBUS_ENABLE_STATS
  75   int total_match_rules;
  76   int peak_match_rules;
  77   int peak_match_rules_per_conn;
  78
  79   int total_bus_names;
  80   int peak_bus_names;
  81   int peak_bus_names_per_conn;
  82 #endif
  83 };
  84
  85 static dbus_int32_t connection_data_slot = -1;
  86
  87 typedef struct
  88 {
  89   BusConnections *connections;
  90   DBusList *link_in_connection_list;
  91   DBusConnection *connection;
  92   DBusList *services_owned;
  93   int n_services_owned;
  94   DBusList *match_rules;
  95   int n_match_rules;
  96   char *name;
  97   DBusList *transaction_messages; /**< Stuff we need to send as part of a transaction */
  98   DBusMessage *oom_message;
  99   DBusPreallocatedSend *oom_preallocated;
 100   BusClientPolicy *policy;
 101
 102   char *cached_loginfo_string;
 103   BusSELinuxID *selinux_id;
 104   BusAppArmorConfinement *apparmor_confinement;
 105
 106   long connection_tv_sec;  /**< Time when we connected (seconds component) */
 107   long connection_tv_usec; /**< Time when we connected (microsec component) */
 108   int stamp;               /**< connections->stamp last time we were traversed */
 109
 110 #ifdef DBUS_ENABLE_STATS
 111   int peak_match_rules;
 112   int peak_bus_names;
 113 #endif
 114   int n_pending_unix_fds;
 115   DBusTimeout *pending_unix_fds_timeout;
 116
 117   /** non-NULL if and only if this is a monitor */
 118   DBusList *link_in_monitors;
 119 } BusConnectionData;
 120
 121 static dbus_bool_t bus_pending_reply_expired (BusExpireList *list,
 122                                               DBusList      *link,
 123                                               void          *data);
 124
 125 static void bus_connection_drop_pending_replies (BusConnections  *connections,
 126                                                  DBusConnection  *connection);
 127
 128 static dbus_bool_t expire_incomplete_timeout (void *data);
 129
 130 #define BUS_CONNECTION_DATA(connection) (dbus_connection_get_data ((connection), connection_data_slot))
 131
 132 static DBusLoop*
 133 connection_get_loop (DBusConnection *connection)
 134 {
 135   BusConnectionData *d;
 136
 137   d = BUS_CONNECTION_DATA (connection);
 138   _dbus_assert(d != NULL);
 139
 140   return bus_context_get_loop (d->connections->context);
 141 }
 142
 143
 144 static int
 145 get_connections_for_uid (BusConnections *connections,
 146                          dbus_uid_t      uid)
 147 {
 148   void *val;
 149   int current_count;
 150
 151   /* val is NULL is 0 when it isn't in the hash yet */
 152
 153   val = _dbus_hash_table_lookup_uintptr (connections->completed_by_user,
 154                                        uid);
 155
 156   current_count = _DBUS_POINTER_TO_INT (val);
 157
 158   return current_count;
 159 }
 160
 161 static dbus_bool_t
 162 adjust_connections_for_uid (BusConnections *connections,
 163                             dbus_uid_t      uid,
 164                             int             adjustment)
 165 {
 166   int current_count;
 167
 168   current_count = get_connections_for_uid (connections, uid);
 169
 170   _dbus_verbose ("Adjusting connection count for UID " DBUS_UID_FORMAT
 171                  ": was %d adjustment %d making %d\n",
 172                  uid, current_count, adjustment, current_count + adjustment);
 173
 174   _dbus_assert (current_count >= 0);
 175
 176   current_count += adjustment;
 177
 178   _dbus_assert (current_count >= 0);
 179
 180   if (current_count == 0)
 181     {
 182       _dbus_hash_table_remove_uintptr (connections->completed_by_user, uid);
 183       return TRUE;
 184     }
 185   else
 186     {
 187       dbus_bool_t retval;
 188
 189       retval = _dbus_hash_table_insert_uintptr (connections->completed_by_user,
 190                                               uid, _DBUS_INT_TO_POINTER (current_count));
 191
 192       /* only positive adjustment can fail as otherwise
 193        * a hash entry should already exist
 194        */
 195       _dbus_assert (adjustment > 0 ||
 196                     (adjustment <= 0 && retval));
 197
 198       return retval;
 199     }
 200 }
 201
 202 void
 203 bus_connection_disconnected (DBusConnection *connection)
 204 {
 205   BusConnectionData *d;
 206   BusService *service;
 207   BusMatchmaker *matchmaker;
 208
 209   d = BUS_CONNECTION_DATA (connection);
 210   _dbus_assert (d != NULL);
 211
 212   _dbus_verbose ("%s disconnected, dropping all service ownership and releasing\n",
 213                  d->name ? d->name : "(inactive)");
 214
 215   /* Delete our match rules */
 216   if (d->n_match_rules > 0)
 217     {
 218       matchmaker = bus_context_get_matchmaker (d->connections->context);
 219       bus_matchmaker_disconnected (matchmaker, connection);
 220     }
 221
 222   /* Drop any service ownership. Unfortunately, this requires
 223    * memory allocation and there doesn't seem to be a good way to
 224    * handle it other than sleeping; we can't "fail" the operation of
 225    * disconnecting a client, and preallocating a broadcast "service is
 226    * now gone" message for every client-service pair seems kind of
 227    * involved.
 228    */
 229   while ((service = _dbus_list_get_last (&d->services_owned)))
 230     {
 231       BusTransaction *transaction;
 232       DBusError error;
 233
 234     retry:
 235
 236       dbus_error_init (&error);
 237
 238       while ((transaction = bus_transaction_new (d->connections->context)) == NULL)
 239         _dbus_wait_for_memory ();
 240
 241       if (!bus_service_remove_owner (service, connection,
 242                                      transaction, &error))
 243         {
 244           _DBUS_ASSERT_ERROR_IS_SET (&error);
 245
 246           if (dbus_error_has_name (&error, DBUS_ERROR_NO_MEMORY))
 247             {
 248               dbus_error_free (&error);
 249               bus_transaction_cancel_and_free (transaction);
 250               _dbus_wait_for_memory ();
 251               goto retry;
 252             }
 253           else
 254             {
 255               _dbus_verbose ("Failed to remove service owner: %s %s\n",
 256                              error.name, error.message);
 257               _dbus_assert_not_reached ("Removing service owner failed for non-memory-related reason");
 258             }
 259         }
 260
 261       bus_transaction_execute_and_free (transaction);
 262     }
 263
 264   bus_dispatch_remove_connection (connection);
 265
 266   /* no more watching */
 267   if (!dbus_connection_set_watch_functions (connection,
 268                                             NULL, NULL, NULL,
 269                                             connection,
 270                                             NULL))
 271     _dbus_assert_not_reached ("setting watch functions to NULL failed");
 272
 273   if (!dbus_connection_set_timeout_functions (connection,
 274                                               NULL, NULL, NULL,
 275                                               connection,
 276                                               NULL))
 277     _dbus_assert_not_reached ("setting timeout functions to NULL failed");
 278
 279   dbus_connection_set_unix_user_function (connection,
 280                                           NULL, NULL, NULL);
 281   dbus_connection_set_windows_user_function (connection,
 282                                              NULL, NULL, NULL);
 283
 284   dbus_connection_set_dispatch_status_function (connection,
 285                                                 NULL, NULL, NULL);
 286
 287   if (d->pending_unix_fds_timeout)
 288     {
 289       _dbus_loop_remove_timeout (bus_context_get_loop (d->connections->context),
 290                                  d->pending_unix_fds_timeout);
 291       _dbus_timeout_unref (d->pending_unix_fds_timeout);
 292     }
 293   d->pending_unix_fds_timeout = NULL;
 294   _dbus_connection_set_pending_fds_function (connection, NULL, NULL);
 295
 296   bus_connection_remove_transactions (connection);
 297
 298   if (d->link_in_monitors != NULL)
 299     {
 300       BusMatchmaker *mm = d->connections->monitor_matchmaker;
 301
 302       if (mm != NULL)
 303         bus_matchmaker_disconnected (mm, connection);
 304
 305       _dbus_list_remove_link (&d->connections->monitors, d->link_in_monitors);
 306       d->link_in_monitors = NULL;
 307     }
 308
 309   if (d->link_in_connection_list != NULL)
 310     {
 311       if (d->name != NULL)
 312         {
 313           unsigned long uid;
 314
 315           _dbus_list_remove_link (&d->connections->completed, d->link_in_connection_list);
 316           d->link_in_connection_list = NULL;
 317           d->connections->n_completed -= 1;
 318
 319           if (dbus_connection_get_unix_user (connection, &uid))
 320             {
 321               if (!adjust_connections_for_uid (d->connections,
 322                                                uid, -1))
 323                 _dbus_assert_not_reached ("adjusting downward should never fail");
 324             }
 325         }
 326       else
 327         {
 328           _dbus_list_remove_link (&d->connections->incomplete, d->link_in_connection_list);
 329           d->link_in_connection_list = NULL;
 330           d->connections->n_incomplete -= 1;
 331
 332           /* If we have dropped below the max. number of incomplete
 333            * connections, start accept()ing again */
 334           bus_context_check_all_watches (d->connections->context);
 335         }
 336
 337       _dbus_assert (d->connections->n_incomplete >= 0);
 338       _dbus_assert (d->connections->n_completed >= 0);
 339     }
 340
 341   bus_connection_drop_pending_replies (d->connections, connection);
 342
 343   /* frees "d" as side effect */
 344   dbus_connection_set_data (connection,
 345                             connection_data_slot,
 346                             NULL, NULL);
 347
 348   dbus_connection_unref (connection);
 349 }
 350
 351 static dbus_bool_t
 352 add_connection_watch (DBusWatch      *watch,
 353                       void           *data)
 354 {
 355   DBusConnection *connection = data;
 356
 357   return _dbus_loop_add_watch (connection_get_loop (connection), watch);
 358 }
 359
 360 static void
 361 remove_connection_watch (DBusWatch      *watch,
 362                          void           *data)
 363 {
 364   DBusConnection *connection = data;
 365
 366   _dbus_loop_remove_watch (connection_get_loop (connection), watch);
 367 }
 368
 369 static void
 370 toggle_connection_watch (DBusWatch      *watch,
 371                          void           *data)
 372 {
 373   DBusConnection *connection = data;
 374
 375   _dbus_loop_toggle_watch (connection_get_loop (connection), watch);
 376 }
 377
 378 static dbus_bool_t
 379 add_connection_timeout (DBusTimeout    *timeout,
 380                         void           *data)
 381 {
 382   DBusConnection *connection = data;
 383
 384   return _dbus_loop_add_timeout (connection_get_loop (connection), timeout);
 385 }
 386
 387 static void
 388 remove_connection_timeout (DBusTimeout    *timeout,
 389                            void           *data)
 390 {
 391   DBusConnection *connection = data;
 392
 393   _dbus_loop_remove_timeout (connection_get_loop (connection), timeout);
 394 }
 395
 396 static void
 397 dispatch_status_function (DBusConnection    *connection,
 398                           DBusDispatchStatus new_status,
 399                           void              *data)
 400 {
 401   DBusLoop *loop = data;
 402
 403   if (new_status != DBUS_DISPATCH_COMPLETE)
 404     {
 405       while (!_dbus_loop_queue_dispatch (loop, connection))
 406         _dbus_wait_for_memory ();
 407     }
 408 }
 409
 410 static dbus_bool_t
 411 allow_unix_user_function (DBusConnection *connection,
 412                           unsigned long   uid,
 413                           void           *data)
 414 {
 415   BusConnectionData *d;
 416
 417   d = BUS_CONNECTION_DATA (connection);
 418
 419   _dbus_assert (d != NULL);
 420
 421   return bus_context_allow_unix_user (d->connections->context, uid);
 422 }
 423
 424 static void
 425 free_connection_data (void *data)
 426 {
 427   BusConnectionData *d = data;
 428
 429   /* services_owned should be NULL since we should be disconnected */
 430   _dbus_assert (d->services_owned == NULL);
 431   _dbus_assert (d->n_services_owned == 0);
 432   /* similarly */
 433   _dbus_assert (d->transaction_messages == NULL);
 434
 435   if (d->oom_preallocated)
 436     dbus_connection_free_preallocated_send (d->connection, d->oom_preallocated);
 437
 438   if (d->oom_message)
 439     dbus_message_unref (d->oom_message);
 440
 441   if (d->policy)
 442     bus_client_policy_unref (d->policy);
 443
 444   if (d->selinux_id)
 445     bus_selinux_id_unref (d->selinux_id);
 446
 447   if (d->apparmor_confinement)
 448     bus_apparmor_confinement_unref (d->apparmor_confinement);
 449
 450   dbus_free (d->cached_loginfo_string);
 451
 452   dbus_free (d->name);
 453
 454   dbus_free (d);
 455 }
 456
 457 BusConnections*
 458 bus_connections_new (BusContext *context)
 459 {
 460   BusConnections *connections;
 461
 462   if (!dbus_connection_allocate_data_slot (&connection_data_slot))
 463     goto failed_0;
 464
 465   connections = dbus_new0 (BusConnections, 1);
 466   if (connections == NULL)
 467     goto failed_1;
 468
 469   connections->completed_by_user = _dbus_hash_table_new (DBUS_HASH_UINTPTR,
 470                                                          NULL, NULL);
 471   if (connections->completed_by_user == NULL)
 472     goto failed_2;
 473
 474   connections->expire_timeout = _dbus_timeout_new (100, /* irrelevant */
 475                                                    expire_incomplete_timeout,
 476                                                    connections, NULL);
 477   if (connections->expire_timeout == NULL)
 478     goto failed_3;
 479
 480   _dbus_timeout_set_enabled (connections->expire_timeout, FALSE);
 481
 482   connections->pending_replies = bus_expire_list_new (bus_context_get_loop (context),
 483                                                       bus_context_get_reply_timeout (context),
 484                                                       bus_pending_reply_expired,
 485                                                       connections);
 486   if (connections->pending_replies == NULL)
 487     goto failed_4;
 488
 489   if (!_dbus_loop_add_timeout (bus_context_get_loop (context),
 490                                connections->expire_timeout))
 491     goto failed_5;
 492
 493   connections->refcount = 1;
 494   connections->context = context;
 495
 496   return connections;
 497
 498  failed_5:
 499   bus_expire_list_free (connections->pending_replies);
 500  failed_4:
 501   _dbus_timeout_unref (connections->expire_timeout);
 502  failed_3:
 503   _dbus_hash_table_unref (connections->completed_by_user);
 504  failed_2:
 505   dbus_free (connections);
 506  failed_1:
 507   dbus_connection_free_data_slot (&connection_data_slot);
 508  failed_0:
 509   return NULL;
 510 }
 511
 512 BusConnections *
 513 bus_connections_ref (BusConnections *connections)
 514 {
 515   _dbus_assert (connections->refcount > 0);
 516   connections->refcount += 1;
 517
 518   return connections;
 519 }
 520
 521 void
 522 bus_connections_unref (BusConnections *connections)
 523 {
 524   _dbus_assert (connections->refcount > 0);
 525   connections->refcount -= 1;
 526   if (connections->refcount == 0)
 527     {
 528       /* drop all incomplete */
 529       while (connections->incomplete != NULL)
 530         {
 531           DBusConnection *connection;
 532
 533           connection = connections->incomplete->data;
 534
 535           dbus_connection_ref (connection);
 536           dbus_connection_close (connection);
 537           bus_connection_disconnected (connection);
 538           dbus_connection_unref (connection);
 539         }
 540
 541       _dbus_assert (connections->n_incomplete == 0);
 542
 543       /* drop all monitors */
 544       _dbus_list_clear (&connections->monitors);
 545
 546       /* drop all real connections */
 547       while (connections->completed != NULL)
 548         {
 549           DBusConnection *connection;
 550
 551           connection = connections->completed->data;
 552
 553           dbus_connection_ref (connection);
 554           dbus_connection_close (connection);
 555           bus_connection_disconnected (connection);
 556           dbus_connection_unref (connection);
 557         }
 558
 559       _dbus_assert (connections->n_completed == 0);
 560
 561       bus_expire_list_free (connections->pending_replies);
 562
 563       _dbus_loop_remove_timeout (bus_context_get_loop (connections->context),
 564                                  connections->expire_timeout);
 565
 566       _dbus_timeout_unref (connections->expire_timeout);
 567
 568       _dbus_hash_table_unref (connections->completed_by_user);
 569
 570       if (connections->monitor_matchmaker != NULL)
 571         bus_matchmaker_unref (connections->monitor_matchmaker);
 572
 573       dbus_free (connections);
 574
 575       dbus_connection_free_data_slot (&connection_data_slot);
 576     }
 577 }
 578
 579 /* Used for logging */
 580 static dbus_bool_t
 581 cache_peer_loginfo_string (BusConnectionData *d,
 582                            DBusConnection    *connection)
 583 {
 584   DBusString loginfo_buf;
 585   unsigned long uid;
 586   unsigned long pid;
 587   char *windows_sid;
 588   dbus_bool_t prev_added;
 589
 590   if (!_dbus_string_init (&loginfo_buf))
 591     return FALSE;
 592
 593   prev_added = FALSE;
 594   if (dbus_connection_get_unix_user (connection, &uid))
 595     {
 596       if (!_dbus_string_append_printf (&loginfo_buf, "uid=%ld", uid))
 597         goto oom;
 598       else
 599         prev_added = TRUE;
 600     }
 601
 602   if (dbus_connection_get_unix_process_id (connection, &pid))
 603     {
 604       if (prev_added)
 605         {
 606           if (!_dbus_string_append_byte (&loginfo_buf, ' '))
 607             goto oom;
 608         }
 609       if (!_dbus_string_append_printf (&loginfo_buf, "pid=%ld comm=\"", pid))
 610         goto oom;
 611       /* Ignore errors here; we may not have permissions to read the
 612        * proc file. */
 613       _dbus_command_for_pid (pid, &loginfo_buf, MAX_LOG_COMMAND_LEN, NULL);
 614       if (!_dbus_string_append_byte (&loginfo_buf, '"'))
 615         goto oom;
 616     }
 617
 618   if (dbus_connection_get_windows_user (connection, &windows_sid))
 619     {
 620       dbus_bool_t did_append;
 621       did_append = _dbus_string_append_printf (&loginfo_buf,
 622                                                "sid=\"%s\" ", windows_sid);
 623       dbus_free (windows_sid);
 624       if (!did_append)
 625         goto oom;
 626     }
 627
 628   if (!_dbus_string_steal_data (&loginfo_buf, &(d->cached_loginfo_string)))
 629     goto oom;
 630
 631   _dbus_string_free (&loginfo_buf);
 632
 633   return TRUE;
 634 oom:
 635    _dbus_string_free (&loginfo_buf);
 636    return FALSE;
 637 }
 638
 639 static void
 640 check_pending_fds_cb (DBusConnection *connection)
 641 {
 642   BusConnectionData *d = BUS_CONNECTION_DATA (connection);
 643   int n_pending_unix_fds_old;
 644   int n_pending_unix_fds_new;
 645
 646   _dbus_assert(d != NULL);
 647
 648   n_pending_unix_fds_old = d->n_pending_unix_fds;
 649   n_pending_unix_fds_new = _dbus_connection_get_pending_fds_count (connection);
 650
 651   _dbus_verbose ("Pending fds count changed on connection %p: %d -> %d\n",
 652                  connection, n_pending_unix_fds_old, n_pending_unix_fds_new);
 653
 654   if (n_pending_unix_fds_old == 0 && n_pending_unix_fds_new > 0)
 655     {
 656       _dbus_timeout_set_interval (d->pending_unix_fds_timeout,
 657               bus_context_get_pending_fd_timeout (d->connections->context));
 658       _dbus_timeout_set_enabled (d->pending_unix_fds_timeout, TRUE);
 659     }
 660
 661   if (n_pending_unix_fds_old > 0 && n_pending_unix_fds_new == 0)
 662     {
 663       _dbus_timeout_set_enabled (d->pending_unix_fds_timeout, FALSE);
 664     }
 665
 666
 667   d->n_pending_unix_fds = n_pending_unix_fds_new;
 668 }
 669
 670 static dbus_bool_t
 671 pending_unix_fds_timeout_cb (void *data)
 672 {
 673   DBusConnection *connection = data;
 674   dbus_connection_close (connection);
 675   return TRUE;
 676 }
 677
 678 dbus_bool_t
 679 bus_connections_setup_connection (BusConnections *connections,
 680                                   DBusConnection *connection)
 681 {
 682
 683   BusConnectionData *d;
 684   dbus_bool_t retval;
 685   DBusError error;
 686
 687
 688   d = dbus_new0 (BusConnectionData, 1);
 689
 690   if (d == NULL)
 691     return FALSE;
 692
 693   d->connections = connections;
 694   d->connection = connection;
 695
 696   _dbus_get_monotonic_time (&d->connection_tv_sec,
 697                             &d->connection_tv_usec);
 698
 699   _dbus_assert (connection_data_slot >= 0);
 700
 701   if (!dbus_connection_set_data (connection,
 702                                  connection_data_slot,
 703                                  d, free_connection_data))
 704     {
 705       dbus_free (d);
 706       return FALSE;
 707     }
 708
 709   dbus_connection_set_route_peer_messages (connection, TRUE);
 710
 711   retval = FALSE;
 712
 713   dbus_error_init (&error);
 714   d->selinux_id = bus_selinux_init_connection_id (connection,
 715                                                   &error);
 716   if (dbus_error_is_set (&error))
 717     {
 718       /* This is a bit bogus because we pretend all errors
 719        * are OOM; this is done because we know that in bus.c
 720        * an OOM error disconnects the connection, which is
 721        * the same thing we want on any other error.
 722        */
 723       dbus_error_free (&error);
 724       goto out;
 725     }
 726
 727   d->apparmor_confinement = bus_apparmor_init_connection_confinement (connection,
 728                                                                       &error);
 729   if (dbus_error_is_set (&error))
 730     {
 731       /* This is a bit bogus because we pretend all errors
 732        * are OOM; this is done because we know that in bus.c
 733        * an OOM error disconnects the connection, which is
 734        * the same thing we want on any other error.
 735        */
 736       dbus_error_free (&error);
 737       goto out;
 738     }
 739
 740   if (!dbus_connection_set_watch_functions (connection,
 741                                             add_connection_watch,
 742                                             remove_connection_watch,
 743                                             toggle_connection_watch,
 744                                             connection,
 745                                             NULL))
 746     goto out;
 747
 748   if (!dbus_connection_set_timeout_functions (connection,
 749                                               add_connection_timeout,
 750                                               remove_connection_timeout,
 751                                               NULL,
 752                                               connection, NULL))
 753     goto out;
 754
 755   /* For now we don't need to set a Windows user function because
 756    * there are no policies in the config file controlling what
 757    * Windows users can connect. The default 'same user that owns the
 758    * bus can connect' behavior of DBusConnection is fine on Windows.
 759    */
 760   dbus_connection_set_unix_user_function (connection,
 761                                           allow_unix_user_function,
 762                                           NULL, NULL);
 763
 764   dbus_connection_set_dispatch_status_function (connection,
 765                                                 dispatch_status_function,
 766                                                 bus_context_get_loop (connections->context),
 767                                                 NULL);
 768
 769   d->link_in_connection_list = _dbus_list_alloc_link (connection);
 770   if (d->link_in_connection_list == NULL)
 771     goto out;
 772
 773   /* Setup the connection with the dispatcher */
 774   if (!bus_dispatch_add_connection (connection))
 775     goto out;
 776
 777   if (dbus_connection_get_dispatch_status (connection) != DBUS_DISPATCH_COMPLETE)
 778     {
 779       if (!_dbus_loop_queue_dispatch (bus_context_get_loop (connections->context), connection))
 780         {
 781           bus_dispatch_remove_connection (connection);
 782           goto out;
 783         }
 784     }
 785
 786   /* Setup pending fds timeout (see #80559) */
 787   d->pending_unix_fds_timeout = _dbus_timeout_new (100, /* irrelevant */
 788                                                    pending_unix_fds_timeout_cb,
 789                                                    connection, NULL);
 790   if (d->pending_unix_fds_timeout == NULL)
 791     goto out;
 792
 793   _dbus_timeout_set_enabled (d->pending_unix_fds_timeout, FALSE);
 794   if (!_dbus_loop_add_timeout (bus_context_get_loop (connections->context),
 795                                d->pending_unix_fds_timeout))
 796     goto out;
 797
 798   _dbus_connection_set_pending_fds_function (connection,
 799           (DBusPendingFdsChangeFunction) check_pending_fds_cb,
 800           connection);
 801
 802   _dbus_list_append_link (&connections->incomplete, d->link_in_connection_list);
 803   connections->n_incomplete += 1;
 804
 805   dbus_connection_ref (connection);
 806
 807   bus_connections_expire_incomplete (connections);
 808
 809   /* The listening socket is removed from the main loop,
 810    * i.e. does not accept(), while n_incomplete is at its
 811    * maximum value; so we shouldn't get here in that case */
 812   _dbus_assert (connections->n_incomplete <=
 813       bus_context_get_max_incomplete_connections (connections->context));
 814
 815   /* If we have the maximum number of incomplete connections,
 816    * stop accept()ing any more, to avert a DoS. See fd.o #80919 */
 817   bus_context_check_all_watches (d->connections->context);
 818
 819   retval = TRUE;
 820
 821  out:
 822   if (!retval)
 823     {
 824       if (d->selinux_id)
 825         bus_selinux_id_unref (d->selinux_id);
 826       d->selinux_id = NULL;
 827
 828       if (d->apparmor_confinement)
 829         bus_apparmor_confinement_unref (d->apparmor_confinement);
 830       d->apparmor_confinement = NULL;
 831
 832       if (!dbus_connection_set_watch_functions (connection,
 833                                                 NULL, NULL, NULL,
 834                                                 connection,
 835                                                 NULL))
 836         _dbus_assert_not_reached ("setting watch functions to NULL failed");
 837
 838       if (!dbus_connection_set_timeout_functions (connection,
 839                                                   NULL, NULL, NULL,
 840                                                   connection,
 841                                                   NULL))
 842         _dbus_assert_not_reached ("setting timeout functions to NULL failed");
 843
 844       dbus_connection_set_unix_user_function (connection,
 845                                               NULL, NULL, NULL);
 846
 847       dbus_connection_set_windows_user_function (connection,
 848                                                  NULL, NULL, NULL);
 849
 850       dbus_connection_set_dispatch_status_function (connection,
 851                                                     NULL, NULL, NULL);
 852
 853       if (d->pending_unix_fds_timeout)
 854         _dbus_timeout_unref (d->pending_unix_fds_timeout);
 855
 856       d->pending_unix_fds_timeout = NULL;
 857
 858       _dbus_connection_set_pending_fds_function (connection, NULL, NULL);
 859
 860       if (d->link_in_connection_list != NULL)
 861         {
 862           _dbus_assert (d->link_in_connection_list->next == NULL);
 863           _dbus_assert (d->link_in_connection_list->prev == NULL);
 864           _dbus_list_free_link (d->link_in_connection_list);
 865           d->link_in_connection_list = NULL;
 866         }
 867
 868       if (!dbus_connection_set_data (connection,
 869                                      connection_data_slot,
 870                                      NULL, NULL))
 871         _dbus_assert_not_reached ("failed to set connection data to null");
 872
 873       /* "d" has now been freed */
 874     }
 875
 876   return retval;
 877 }
 878
 879 void
 880 bus_connections_expire_incomplete (BusConnections *connections)
 881 {
 882   int next_interval;
 883
 884   next_interval = -1;
 885
 886   if (connections->incomplete != NULL)
 887     {
 888       long tv_sec, tv_usec;
 889       DBusList *link;
 890       int auth_timeout;
 891
 892       _dbus_get_monotonic_time (&tv_sec, &tv_usec);
 893       auth_timeout = bus_context_get_auth_timeout (connections->context);
 894
 895       link = _dbus_list_get_first_link (&connections->incomplete);
 896       while (link != NULL)
 897         {
 898           DBusList *next = _dbus_list_get_next_link (&connections->incomplete, link);
 899           DBusConnection *connection;
 900           BusConnectionData *d;
 901           double elapsed;
 902
 903           connection = link->data;
 904
 905           d = BUS_CONNECTION_DATA (connection);
 906
 907           _dbus_assert (d != NULL);
 908
 909           elapsed = ELAPSED_MILLISECONDS_SINCE (d->connection_tv_sec,
 910                                                 d->connection_tv_usec,
 911                                                 tv_sec, tv_usec);
 912
 913           if (elapsed >= (double) auth_timeout)
 914             {
 915               /* Unfortunately, we can't identify the connection: it doesn't
 916                * have a unique name yet, we don't know its uid/pid yet,
 917                * and so on. */
 918               bus_context_log (connections->context, DBUS_SYSTEM_LOG_WARNING,
 919                   "Connection has not authenticated soon enough, closing it "
 920                   "(auth_timeout=%dms, elapsed: %.0fms)",
 921                   auth_timeout, elapsed);
 922
 923               _dbus_verbose ("Timing out authentication for connection %p\n", connection);
 924               dbus_connection_close (connection);
 925             }
 926           else
 927             {
 928               /* We can end the loop, since the connections are in oldest-first order */
 929               next_interval = ((double)auth_timeout) - elapsed;
 930               _dbus_verbose ("Connection %p authentication expires in %d milliseconds\n",
 931                              connection, next_interval);
 932
 933               break;
 934             }
 935
 936           link = next;
 937         }
 938     }
 939
 940   bus_expire_timeout_set_interval (connections->expire_timeout,
 941                                    next_interval);
 942 }
 943
 944 static dbus_bool_t
 945 expire_incomplete_timeout (void *data)
 946 {
 947   BusConnections *connections = data;
 948
 949   _dbus_verbose ("Running\n");
 950
 951   /* note that this may remove the timeout */
 952   bus_connections_expire_incomplete (connections);
 953
 954   return TRUE;
 955 }
 956
 957 dbus_bool_t
 958 bus_connection_get_unix_groups  (DBusConnection   *connection,
 959                                  unsigned long   **groups,
 960                                  int              *n_groups,
 961                                  DBusError        *error)
 962 {
 963   unsigned long uid;
 964
 965   *groups = NULL;
 966   *n_groups = 0;
 967
 968   if (dbus_connection_get_unix_user (connection, &uid))
 969     {
 970       if (!_dbus_unix_groups_from_uid (uid, groups, n_groups))
 971         {
 972           _dbus_verbose ("Did not get any groups for UID %lu\n",
 973                          uid);
 974           return FALSE;
 975         }
 976       else
 977         {
 978           _dbus_verbose ("Got %d groups for UID %lu\n",
 979                          *n_groups, uid);
 980           return TRUE;
 981         }
 982     }
 983   else
 984     return TRUE; /* successfully got 0 groups */
 985 }
 986
 987 dbus_bool_t
 988 bus_connection_is_in_unix_group (DBusConnection *connection,
 989                                  unsigned long   gid)
 990 {
 991   int i;
 992   unsigned long *group_ids;
 993   int n_group_ids;
 994
 995   if (!bus_connection_get_unix_groups (connection, &group_ids, &n_group_ids,
 996                                        NULL))
 997     return FALSE;
 998
 999   i = 0;
1000   while (i < n_group_ids)
1001     {
1002       if (group_ids[i] == gid)
1003         {
1004           dbus_free (group_ids);
1005           return TRUE;
1006         }
1007       ++i;
1008     }
1009
1010   dbus_free (group_ids);
1011   return FALSE;
1012 }
1013
1014 const char *
1015 bus_connection_get_loginfo (DBusConnection        *connection)
1016 {
1017   BusConnectionData *d;
1018
1019   d = BUS_CONNECTION_DATA (connection);
1020   _dbus_assert(d != NULL);
1021
1022   if (!bus_connection_is_active (connection))
1023     return "inactive";
1024   return d->cached_loginfo_string;
1025 }
1026
1027 BusClientPolicy*
1028 bus_connection_get_policy (DBusConnection *connection)
1029 {
1030   BusConnectionData *d;
1031
1032   d = BUS_CONNECTION_DATA (connection);
1033
1034   _dbus_assert (d != NULL);
1035   _dbus_assert (d->policy != NULL);
1036
1037   return d->policy;
1038 }
1039
1040 static dbus_bool_t
1041 foreach_active (BusConnections               *connections,
1042                 BusConnectionForeachFunction  function,
1043                 void                         *data)
1044 {
1045   DBusList *link;
1046
1047   link = _dbus_list_get_first_link (&connections->completed);
1048   while (link != NULL)
1049     {
1050       DBusConnection *connection = link->data;
1051       DBusList *next = _dbus_list_get_next_link (&connections->completed, link);
1052
1053       if (!(* function) (connection, data))
1054         return FALSE;
1055
1056       link = next;
1057     }
1058
1059   return TRUE;
1060 }
1061
1062 static dbus_bool_t
1063 foreach_inactive (BusConnections               *connections,
1064                   BusConnectionForeachFunction  function,
1065                   void                         *data)
1066 {
1067   DBusList *link;
1068
1069   link = _dbus_list_get_first_link (&connections->incomplete);
1070   while (link != NULL)
1071     {
1072       DBusConnection *connection = link->data;
1073       DBusList *next = _dbus_list_get_next_link (&connections->incomplete, link);
1074
1075       if (!(* function) (connection, data))
1076         return FALSE;
1077
1078       link = next;
1079     }
1080
1081   return TRUE;
1082 }
1083
1084 /**
1085  * Calls function on each active connection; if the function returns
1086  * #FALSE, stops iterating. Active connections are authenticated
1087  * and have sent a Hello message.
1088  *
1089  * @param connections the connections object
1090  * @param function the function
1091  * @param data data to pass to it as a second arg
1092  */
1093 void
1094 bus_connections_foreach_active (BusConnections               *connections,
1095                                 BusConnectionForeachFunction  function,
1096                                 void                         *data)
1097 {
1098   foreach_active (connections, function, data);
1099 }
1100
1101 /**
1102  * Calls function on each connection; if the function returns
1103  * #FALSE, stops iterating.
1104  *
1105  * @param connections the connections object
1106  * @param function the function
1107  * @param data data to pass to it as a second arg
1108  */
1109 void
1110 bus_connections_foreach (BusConnections               *connections,
1111                          BusConnectionForeachFunction  function,
1112                          void                         *data)
1113 {
1114   if (!foreach_active (connections, function, data))
1115     return;
1116
1117   foreach_inactive (connections, function, data);
1118 }
1119
1120 BusContext*
1121 bus_connections_get_context (BusConnections *connections)
1122 {
1123   return connections->context;
1124 }
1125
1126 /*
1127  * This is used to avoid covering the same connection twice when
1128  * traversing connections. Note that it assumes we will
1129  * bus_connection_mark_stamp() each connection at least once per
1130  * INT_MAX increments of the global stamp, or wraparound would break
1131  * things.
1132  */
1133 void
1134 bus_connections_increment_stamp (BusConnections *connections)
1135 {
1136   connections->stamp += 1;
1137 }
1138
1139 /* Mark connection with current stamp, return TRUE if it
1140  * didn't already have that stamp
1141  */
1142 dbus_bool_t
1143 bus_connection_mark_stamp (DBusConnection *connection)
1144 {
1145   BusConnectionData *d;
1146
1147   d = BUS_CONNECTION_DATA (connection);
1148
1149   _dbus_assert (d != NULL);
1150
1151   if (d->stamp == d->connections->stamp)
1152     return FALSE;
1153   else
1154     {
1155       d->stamp = d->connections->stamp;
1156       return TRUE;
1157     }
1158 }
1159
1160 BusContext*
1161 bus_connection_get_context (DBusConnection *connection)
1162 {
1163   BusConnectionData *d;
1164
1165   d = BUS_CONNECTION_DATA (connection);
1166
1167   _dbus_assert (d != NULL);
1168
1169   return d->connections->context;
1170 }
1171
1172 BusConnections*
1173 bus_connection_get_connections (DBusConnection *connection)
1174 {
1175   BusConnectionData *d;
1176
1177   d = BUS_CONNECTION_DATA (connection);
1178
1179   _dbus_assert (d != NULL);
1180
1181   return d->connections;
1182 }
1183
1184 BusRegistry*
1185 bus_connection_get_registry (DBusConnection *connection)
1186 {
1187   BusConnectionData *d;
1188
1189   d = BUS_CONNECTION_DATA (connection);
1190
1191   _dbus_assert (d != NULL);
1192
1193   return bus_context_get_registry (d->connections->context);
1194 }
1195
1196 BusActivation*
1197 bus_connection_get_activation (DBusConnection *connection)
1198 {
1199   BusConnectionData *d;
1200
1201   d = BUS_CONNECTION_DATA (connection);
1202
1203   _dbus_assert (d != NULL);
1204
1205   return bus_context_get_activation (d->connections->context);
1206 }
1207
1208 BusMatchmaker*
1209 bus_connection_get_matchmaker (DBusConnection *connection)
1210 {
1211   BusConnectionData *d;
1212
1213   d = BUS_CONNECTION_DATA (connection);
1214
1215   _dbus_assert (d != NULL);
1216
1217   return bus_context_get_matchmaker (d->connections->context);
1218 }
1219
1220 BusSELinuxID*
1221 bus_connection_get_selinux_id (DBusConnection *connection)
1222 {
1223   BusConnectionData *d;
1224
1225   d = BUS_CONNECTION_DATA (connection);
1226
1227   _dbus_assert (d != NULL);
1228
1229   return d->selinux_id;
1230 }
1231
1232 BusAppArmorConfinement*
1233 bus_connection_dup_apparmor_confinement (DBusConnection *connection)
1234 {
1235   BusConnectionData *d;
1236
1237   d = BUS_CONNECTION_DATA (connection);
1238
1239   _dbus_assert (d != NULL);
1240
1241   bus_apparmor_confinement_ref (d->apparmor_confinement);
1242   return d->apparmor_confinement;
1243 }
1244
1245 /**
1246  * Checks whether the connection is registered with the message bus.
1247  *
1248  * @param connection the connection
1249  * @returns #TRUE if we're an active message bus participant
1250  */
1251 dbus_bool_t
1252 bus_connection_is_active (DBusConnection *connection)
1253 {
1254   BusConnectionData *d;
1255
1256   d = BUS_CONNECTION_DATA (connection);
1257   _dbus_assert(d != NULL);
1258
1259   return d->name != NULL;
1260 }
1261
1262 dbus_bool_t
1263 bus_connection_preallocate_oom_error (DBusConnection *connection)
1264 {
1265   DBusMessage *message;
1266   DBusPreallocatedSend *preallocated;
1267   BusConnectionData *d;
1268
1269   d = BUS_CONNECTION_DATA (connection);
1270
1271   _dbus_assert (d != NULL);
1272
1273   if (d->oom_preallocated != NULL)
1274     return TRUE;
1275
1276   preallocated = dbus_connection_preallocate_send (connection);
1277   if (preallocated == NULL)
1278     return FALSE;
1279
1280   message = dbus_message_new (DBUS_MESSAGE_TYPE_ERROR);
1281
1282   if (message == NULL)
1283     {
1284       dbus_connection_free_preallocated_send (connection, preallocated);
1285       return FALSE;
1286     }
1287
1288   /* d->name may be NULL, but that is OK */
1289   if (!dbus_message_set_error_name (message, DBUS_ERROR_NO_MEMORY) ||
1290       !dbus_message_set_destination (message, d->name) ||
1291       !dbus_message_set_sender (message,
1292                                 DBUS_SERVICE_DBUS))
1293     {
1294       dbus_connection_free_preallocated_send (connection, preallocated);
1295       dbus_message_unref (message);
1296       return FALSE;
1297     }
1298
1299   /* set reply serial to placeholder value just so space is already allocated
1300    * for it.
1301    */
1302   if (!dbus_message_set_reply_serial (message, 14))
1303     {
1304       dbus_connection_free_preallocated_send (connection, preallocated);
1305       dbus_message_unref (message);
1306       return FALSE;
1307     }
1308
1309   d->oom_message = message;
1310   d->oom_preallocated = preallocated;
1311
1312   return TRUE;
1313 }
1314
1315 void
1316 bus_connection_send_oom_error (DBusConnection *connection,
1317                                DBusMessage    *in_reply_to)
1318 {
1319   BusConnectionData *d;
1320
1321   d = BUS_CONNECTION_DATA (connection);
1322
1323   _dbus_assert (d != NULL);
1324   _dbus_assert (d->oom_message != NULL);
1325
1326   bus_context_log (d->connections->context, DBUS_SYSTEM_LOG_WARNING,
1327                    "dbus-daemon transaction failed (OOM), sending error to "
1328                    "sender %s", bus_connection_get_loginfo (connection));
1329
1330   /* should always succeed since we set it to a placeholder earlier */
1331   if (!dbus_message_set_reply_serial (d->oom_message,
1332                                       dbus_message_get_serial (in_reply_to)))
1333     _dbus_assert_not_reached ("Failed to set reply serial for preallocated oom message");
1334
1335   _dbus_assert (dbus_message_get_sender (d->oom_message) != NULL);
1336
1337   dbus_connection_send_preallocated (connection, d->oom_preallocated,
1338                                      d->oom_message, NULL);
1339
1340   dbus_message_unref (d->oom_message);
1341   d->oom_message = NULL;
1342   d->oom_preallocated = NULL;
1343 }
1344
1345 #ifdef DBUS_ENABLE_STATS
1346 static void
1347 update_peak (int *peak,
1348              int n)
1349 {
1350   if (*peak < n)
1351     *peak = n;
1352 }
1353 #endif
1354
1355 void
1356 bus_connection_add_match_rule_link (DBusConnection *connection,
1357                                     DBusList       *link)
1358 {
1359   BusConnectionData *d;
1360
1361   d = BUS_CONNECTION_DATA (connection);
1362   _dbus_assert (d != NULL);
1363
1364   _dbus_list_append_link (&d->match_rules, link);
1365
1366   d->n_match_rules += 1;
1367
1368 #ifdef DBUS_ENABLE_STATS
1369   update_peak (&d->peak_match_rules, d->n_match_rules);
1370   update_peak (&d->connections->peak_match_rules_per_conn, d->n_match_rules);
1371
1372   d->connections->total_match_rules += 1;
1373   update_peak (&d->connections->peak_match_rules,
1374                d->connections->total_match_rules);
1375 #endif
1376 }
1377
1378 dbus_bool_t
1379 bus_connection_add_match_rule (DBusConnection *connection,
1380                                BusMatchRule   *rule)
1381 {
1382     DBusList *link;
1383
1384   link = _dbus_list_alloc_link (rule);
1385
1386   if (link == NULL)
1387     return FALSE;
1388
1389   bus_connection_add_match_rule_link (connection, link);
1390
1391   return TRUE;
1392 }
1393
1394 void
1395 bus_connection_remove_match_rule (DBusConnection *connection,
1396                                   BusMatchRule   *rule)
1397 {
1398   BusConnectionData *d;
1399
1400   d = BUS_CONNECTION_DATA (connection);
1401   _dbus_assert (d != NULL);
1402
1403   _dbus_list_remove_last (&d->match_rules, rule);
1404
1405   d->n_match_rules -= 1;
1406   _dbus_assert (d->n_match_rules >= 0);
1407
1408 #ifdef DBUS_ENABLE_STATS
1409   d->connections->total_match_rules -= 1;
1410 #endif
1411 }
1412
1413 int
1414 bus_connection_get_n_match_rules (DBusConnection *connection)
1415 {
1416   BusConnectionData *d;
1417
1418   d = BUS_CONNECTION_DATA (connection);
1419   _dbus_assert (d != NULL);
1420
1421   return d->n_match_rules;
1422 }
1423
1424 void
1425 bus_connection_add_owned_service_link (DBusConnection *connection,
1426                                        DBusList       *link)
1427 {
1428   BusConnectionData *d;
1429
1430   d = BUS_CONNECTION_DATA (connection);
1431   _dbus_assert (d != NULL);
1432
1433   _dbus_list_append_link (&d->services_owned, link);
1434
1435   d->n_services_owned += 1;
1436
1437 #ifdef DBUS_ENABLE_STATS
1438   update_peak (&d->peak_bus_names, d->n_services_owned);
1439   update_peak (&d->connections->peak_bus_names_per_conn,
1440                d->n_services_owned);
1441
1442   d->connections->total_bus_names += 1;
1443   update_peak (&d->connections->peak_bus_names,
1444                d->connections->total_bus_names);
1445 #endif
1446 }
1447
1448 dbus_bool_t
1449 bus_connection_add_owned_service (DBusConnection *connection,
1450                                   BusService     *service)
1451 {
1452   DBusList *link;
1453
1454   link = _dbus_list_alloc_link (service);
1455
1456   if (link == NULL)
1457     return FALSE;
1458
1459   bus_connection_add_owned_service_link (connection, link);
1460
1461   return TRUE;
1462 }
1463
1464 void
1465 bus_connection_remove_owned_service (DBusConnection *connection,
1466                                      BusService     *service)
1467 {
1468   BusConnectionData *d;
1469
1470   d = BUS_CONNECTION_DATA (connection);
1471   _dbus_assert (d != NULL);
1472
1473   _dbus_list_remove_last (&d->services_owned, service);
1474
1475   d->n_services_owned -= 1;
1476   _dbus_assert (d->n_services_owned >= 0);
1477
1478 #ifdef DBUS_ENABLE_STATS
1479   d->connections->total_bus_names -= 1;
1480 #endif
1481 }
1482
1483 int
1484 bus_connection_get_n_services_owned (DBusConnection *connection)
1485 {
1486   BusConnectionData *d;
1487
1488   d = BUS_CONNECTION_DATA (connection);
1489   _dbus_assert (d != NULL);
1490
1491   return d->n_services_owned;
1492 }
1493
1494 dbus_bool_t
1495 bus_connection_complete (DBusConnection   *connection,
1496                          const DBusString *name,
1497                          DBusError        *error)
1498 {
1499   BusConnectionData *d;
1500   unsigned long uid;
1501
1502   d = BUS_CONNECTION_DATA (connection);
1503   _dbus_assert (d != NULL);
1504   _dbus_assert (d->name == NULL);
1505   _dbus_assert (d->policy == NULL);
1506
1507   _dbus_assert (!bus_connection_is_active (connection));
1508
1509   if (!_dbus_string_copy_data (name, &d->name))
1510     {
1511       BUS_SET_OOM (error);
1512       return FALSE;
1513     }
1514
1515   _dbus_assert (d->name != NULL);
1516
1517   _dbus_verbose ("Name %s assigned to %p\n", d->name, connection);
1518
1519   d->policy = bus_context_create_client_policy (d->connections->context,
1520                                                 connection,
1521                                                 error);
1522
1523   /* we may have a NULL policy on OOM or error getting list of
1524    * groups for a user. In the latter case we don't handle it so
1525    * well currently, as it will just keep failing over and over.
1526    */
1527
1528   if (d->policy == NULL)
1529     {
1530       _dbus_verbose ("Failed to create security policy for connection %p\n",
1531                      connection);
1532       _DBUS_ASSERT_ERROR_IS_SET (error);
1533       dbus_free (d->name);
1534       d->name = NULL;
1535       return FALSE;
1536     }
1537
1538   if (dbus_connection_get_unix_user (connection, &uid))
1539     {
1540       if (!adjust_connections_for_uid (d->connections,
1541                                        uid, 1))
1542         goto fail;
1543     }
1544
1545   /* Create and cache a string which holds information about the
1546    * peer process; used for logging purposes.
1547    */
1548   if (!cache_peer_loginfo_string (d, connection))
1549     goto fail;
1550
1551   /* Now the connection is active, move it between lists */
1552   _dbus_list_unlink (&d->connections->incomplete,
1553                      d->link_in_connection_list);
1554   d->connections->n_incomplete -= 1;
1555   _dbus_list_append_link (&d->connections->completed,
1556                           d->link_in_connection_list);
1557   d->connections->n_completed += 1;
1558
1559   _dbus_assert (d->connections->n_incomplete >= 0);
1560   _dbus_assert (d->connections->n_completed > 0);
1561
1562   /* If we have dropped below the max. number of incomplete
1563    * connections, start accept()ing again */
1564   bus_context_check_all_watches (d->connections->context);
1565
1566   /* See if we can remove the timeout */
1567   bus_connections_expire_incomplete (d->connections);
1568
1569   _dbus_assert (bus_connection_is_active (connection));
1570
1571   return TRUE;
1572 fail:
1573   BUS_SET_OOM (error);
1574   dbus_free (d->name);
1575   d->name = NULL;
1576   if (d->policy)
1577     bus_client_policy_unref (d->policy);
1578   d->policy = NULL;
1579   return FALSE;
1580 }
1581
1582 dbus_bool_t
1583 bus_connections_reload_policy (BusConnections *connections,
1584                                DBusError      *error)
1585 {
1586   BusConnectionData *d;
1587   DBusConnection *connection;
1588   DBusList *link;
1589
1590   _dbus_assert (connections != NULL);
1591   _DBUS_ASSERT_ERROR_IS_CLEAR (error);
1592
1593   for (link = _dbus_list_get_first_link (&(connections->completed));
1594        link;
1595        link = _dbus_list_get_next_link (&(connections->completed), link))
1596     {
1597       connection = link->data;
1598       d = BUS_CONNECTION_DATA (connection);
1599       _dbus_assert (d != NULL);
1600       _dbus_assert (d->policy != NULL);
1601
1602       bus_client_policy_unref (d->policy);
1603       d->policy = bus_context_create_client_policy (connections->context,
1604                                                     connection,
1605                                                     error);
1606       if (d->policy == NULL)
1607         {
1608           _dbus_verbose ("Failed to create security policy for connection %p\n",
1609                       connection);
1610           _DBUS_ASSERT_ERROR_IS_SET (error);
1611           return FALSE;
1612         }
1613     }
1614
1615   return TRUE;
1616 }
1617
1618 const char *
1619 bus_connection_get_name (DBusConnection *connection)
1620 {
1621   BusConnectionData *d;
1622
1623   d = BUS_CONNECTION_DATA (connection);
1624   _dbus_assert (d != NULL);
1625
1626   return d->name;
1627 }
1628
1629 /**
1630  * Check whether completing the passed-in connection would
1631  * exceed limits, and if so set error and return #FALSE
1632  */
1633 dbus_bool_t
1634 bus_connections_check_limits (BusConnections  *connections,
1635                               DBusConnection  *requesting_completion,
1636                               DBusError       *error)
1637 {
1638   unsigned long uid;
1639
1640   if (connections->n_completed >=
1641       bus_context_get_max_completed_connections (connections->context))
1642     {
1643       dbus_set_error (error, DBUS_ERROR_LIMITS_EXCEEDED,
1644                       "The maximum number of active connections has been reached");
1645       return FALSE;
1646     }
1647
1648   if (dbus_connection_get_unix_user (requesting_completion, &uid))
1649     {
1650       if (get_connections_for_uid (connections, uid) >=
1651           bus_context_get_max_connections_per_user (connections->context))
1652         {
1653           dbus_set_error (error, DBUS_ERROR_LIMITS_EXCEEDED,
1654                           "The maximum number of active connections for UID %lu has been reached",
1655                           uid);
1656           return FALSE;
1657         }
1658     }
1659
1660   return TRUE;
1661 }
1662
1663 static void
1664 bus_pending_reply_free (BusPendingReply *pending)
1665 {
1666   _dbus_verbose ("Freeing pending reply %p, replier %p receiver %p serial %u\n",
1667                  pending,
1668                  pending->will_send_reply,
1669                  pending->will_get_reply,
1670                  pending->reply_serial);
1671
1672   dbus_free (pending);
1673 }
1674
1675 static dbus_bool_t
1676 bus_pending_reply_send_no_reply (BusConnections  *connections,
1677                                  BusTransaction  *transaction,
1678                                  BusPendingReply *pending)
1679 {
1680   DBusMessage *message;
1681   DBusMessageIter iter;
1682   dbus_bool_t retval;
1683   const char *errmsg;
1684
1685   retval = FALSE;
1686
1687   message = dbus_message_new (DBUS_MESSAGE_TYPE_ERROR);
1688   if (message == NULL)
1689     return FALSE;
1690
1691   dbus_message_set_no_reply (message, TRUE);
1692
1693   if (!dbus_message_set_reply_serial (message,
1694                                       pending->reply_serial))
1695     goto out;
1696
1697   if (!dbus_message_set_error_name (message,
1698                                     DBUS_ERROR_NO_REPLY))
1699     goto out;
1700
1701   /* If you change these messages, adjust test/dbus-daemon.c to match */
1702   if (pending->will_send_reply == NULL)
1703     errmsg = "Message recipient disconnected from message bus without replying";
1704   else
1705     errmsg = "Message did not receive a reply (timeout by message bus)";
1706
1707   dbus_message_iter_init_append (message, &iter);
1708   if (!dbus_message_iter_append_basic (&iter, DBUS_TYPE_STRING, &errmsg))
1709     goto out;
1710
1711   if (!bus_transaction_send_from_driver (transaction, pending->will_get_reply,
1712                                          message))
1713     goto out;
1714
1715   retval = TRUE;
1716
1717  out:
1718   dbus_message_unref (message);
1719   return retval;
1720 }
1721
1722 static dbus_bool_t
1723 bus_pending_reply_expired (BusExpireList *list,
1724                            DBusList      *link,
1725                            void          *data)
1726 {
1727   BusPendingReply *pending = link->data;
1728   BusConnections *connections = data;
1729   BusTransaction *transaction;
1730
1731   /* No reply is forthcoming. So nuke it if we can. If not,
1732    * leave it in the list to try expiring again later when we
1733    * get more memory.
1734    */
1735
1736   _dbus_verbose ("Expiring pending reply %p, replier %p receiver %p serial %u\n",
1737                  pending,
1738                  pending->will_send_reply,
1739                  pending->will_get_reply,
1740                  pending->reply_serial);
1741
1742   transaction = bus_transaction_new (connections->context);
1743   if (transaction == NULL)
1744     return FALSE;
1745
1746   if (!bus_pending_reply_send_no_reply (connections,
1747                                         transaction,
1748                                         pending))
1749     {
1750       bus_transaction_cancel_and_free (transaction);
1751       return FALSE;
1752     }
1753
1754   bus_expire_list_remove_link (connections->pending_replies, link);
1755
1756   bus_pending_reply_free (pending);
1757   bus_transaction_execute_and_free (transaction);
1758
1759   return TRUE;
1760 }
1761
1762 static void
1763 bus_connection_drop_pending_replies (BusConnections  *connections,
1764                                      DBusConnection  *connection)
1765 {
1766   /* The DBusConnection is almost 100% finalized here, so you can't
1767    * do anything with it except check for pointer equality
1768    */
1769   DBusList *link;
1770
1771   _dbus_verbose ("Dropping pending replies that involve connection %p\n",
1772                  connection);
1773
1774   link = bus_expire_list_get_first_link (connections->pending_replies);
1775   while (link != NULL)
1776     {
1777       DBusList *next;
1778       BusPendingReply *pending;
1779
1780       next = bus_expire_list_get_next_link (connections->pending_replies,
1781                                             link);
1782       pending = link->data;
1783
1784       if (pending->will_get_reply == connection)
1785         {
1786           /* We don't need to track this pending reply anymore */
1787
1788           _dbus_verbose ("Dropping pending reply %p, replier %p receiver %p serial %u\n",
1789                          pending,
1790                          pending->will_send_reply,
1791                          pending->will_get_reply,
1792                          pending->reply_serial);
1793
1794           bus_expire_list_remove_link (connections->pending_replies,
1795                                        link);
1796           bus_pending_reply_free (pending);
1797         }
1798       else if (pending->will_send_reply == connection)
1799         {
1800           /* The reply isn't going to be sent, so set things
1801            * up so it will be expired right away
1802            */
1803           _dbus_verbose ("Will expire pending reply %p, replier %p receiver %p serial %u\n",
1804                          pending,
1805                          pending->will_send_reply,
1806                          pending->will_get_reply,
1807                          pending->reply_serial);
1808
1809           pending->will_send_reply = NULL;
1810           pending->expire_item.added_tv_sec = 0;
1811           pending->expire_item.added_tv_usec = 0;
1812
1813           bus_expire_list_recheck_immediately (connections->pending_replies);
1814         }
1815
1816       link = next;
1817     }
1818 }
1819
1820
1821 typedef struct
1822 {
1823   BusPendingReply *pending;
1824   BusConnections  *connections;
1825 } CancelPendingReplyData;
1826
1827 static void
1828 cancel_pending_reply (void *data)
1829 {
1830   CancelPendingReplyData *d = data;
1831
1832   _dbus_verbose ("d = %p\n", d);
1833
1834   if (!bus_expire_list_remove (d->connections->pending_replies,
1835                                &d->pending->expire_item))
1836     _dbus_assert_not_reached ("pending reply did not exist to be cancelled");
1837
1838   bus_pending_reply_free (d->pending); /* since it's been cancelled */
1839 }
1840
1841 static void
1842 cancel_pending_reply_data_free (void *data)
1843 {
1844   CancelPendingReplyData *d = data;
1845
1846   _dbus_verbose ("d = %p\n", d);
1847
1848   /* d->pending should be either freed or still
1849    * in the list of pending replies (owned by someone
1850    * else)
1851    */
1852
1853   dbus_free (d);
1854 }
1855
1856 /*
1857  * Record that a reply is allowed; return TRUE on success.
1858  */
1859 dbus_bool_t
1860 bus_connections_expect_reply (BusConnections  *connections,
1861                               BusTransaction  *transaction,
1862                               DBusConnection  *will_get_reply,
1863                               DBusConnection  *will_send_reply,
1864                               DBusMessage     *reply_to_this,
1865                               DBusError       *error)
1866 {
1867   BusPendingReply *pending;
1868   dbus_uint32_t reply_serial;
1869   DBusList *link;
1870   CancelPendingReplyData *cprd;
1871   int count;
1872
1873   _dbus_assert (will_get_reply != NULL);
1874   _dbus_assert (will_send_reply != NULL);
1875   _dbus_assert (reply_to_this != NULL);
1876
1877   if (dbus_message_get_no_reply (reply_to_this))
1878     return TRUE; /* we won't allow a reply, since client doesn't care for one. */
1879
1880   reply_serial = dbus_message_get_serial (reply_to_this);
1881
1882   link = bus_expire_list_get_first_link (connections->pending_replies);
1883   count = 0;
1884   while (link != NULL)
1885     {
1886       pending = link->data;
1887
1888       if (pending->reply_serial == reply_serial &&
1889           pending->will_get_reply == will_get_reply &&
1890           pending->will_send_reply == will_send_reply)
1891         {
1892           dbus_set_error (error, DBUS_ERROR_ACCESS_DENIED,
1893                           "Message has the same reply serial as a currently-outstanding existing method call");
1894           return FALSE;
1895         }
1896
1897       link = bus_expire_list_get_next_link (connections->pending_replies,
1898                                             link);
1899       if (pending->will_get_reply == will_get_reply)
1900         ++count;
1901     }
1902
1903   if (count >=
1904       bus_context_get_max_replies_per_connection (connections->context))
1905     {
1906       dbus_set_error (error, DBUS_ERROR_LIMITS_EXCEEDED,
1907                       "The maximum number of pending replies per connection has been reached");
1908       return FALSE;
1909     }
1910
1911   pending = dbus_new0 (BusPendingReply, 1);
1912   if (pending == NULL)
1913     {
1914       BUS_SET_OOM (error);
1915       return FALSE;
1916     }
1917
1918 #ifdef DBUS_ENABLE_VERBOSE_MODE
1919   /* so we can see a not-yet-added pending reply */
1920   pending->expire_item.added_tv_sec = 1;
1921   pending->expire_item.added_tv_usec = 1;
1922 #endif
1923
1924   pending->will_get_reply = will_get_reply;
1925   pending->will_send_reply = will_send_reply;
1926   pending->reply_serial = reply_serial;
1927
1928   cprd = dbus_new0 (CancelPendingReplyData, 1);
1929   if (cprd == NULL)
1930     {
1931       BUS_SET_OOM (error);
1932       bus_pending_reply_free (pending);
1933       return FALSE;
1934     }
1935
1936   if (!bus_expire_list_add (connections->pending_replies,
1937                             &pending->expire_item))
1938     {
1939       BUS_SET_OOM (error);
1940       dbus_free (cprd);
1941       bus_pending_reply_free (pending);
1942       return FALSE;
1943     }
1944
1945   if (!bus_transaction_add_cancel_hook (transaction,
1946                                         cancel_pending_reply,
1947                                         cprd,
1948                                         cancel_pending_reply_data_free))
1949     {
1950       BUS_SET_OOM (error);
1951       bus_expire_list_remove (connections->pending_replies, &pending->expire_item);
1952       dbus_free (cprd);
1953       bus_pending_reply_free (pending);
1954       return FALSE;
1955     }
1956
1957   cprd->pending = pending;
1958   cprd->connections = connections;
1959
1960   _dbus_get_monotonic_time (&pending->expire_item.added_tv_sec,
1961                             &pending->expire_item.added_tv_usec);
1962
1963   _dbus_verbose ("Added pending reply %p, replier %p receiver %p serial %u\n",
1964                  pending,
1965                  pending->will_send_reply,
1966                  pending->will_get_reply,
1967                  pending->reply_serial);
1968
1969   return TRUE;
1970 }
1971
1972 typedef struct
1973 {
1974   DBusList        *link;
1975   BusConnections  *connections;
1976 } CheckPendingReplyData;
1977
1978 static void
1979 cancel_check_pending_reply (void *data)
1980 {
1981   CheckPendingReplyData *d = data;
1982
1983   _dbus_verbose ("d = %p\n",d);
1984
1985   bus_expire_list_add_link (d->connections->pending_replies,
1986                             d->link);
1987   d->link = NULL;
1988 }
1989
1990 static void
1991 check_pending_reply_data_free (void *data)
1992 {
1993   CheckPendingReplyData *d = data;
1994
1995   _dbus_verbose ("d = %p\n",d);
1996
1997   if (d->link != NULL)
1998     {
1999       BusPendingReply *pending = d->link->data;
2000
2001       _dbus_assert (!bus_expire_list_contains_item (d->connections->pending_replies,
2002                                                     &pending->expire_item));
2003
2004       bus_pending_reply_free (pending);
2005       _dbus_list_free_link (d->link);
2006     }
2007
2008   dbus_free (d);
2009 }
2010
2011 /*
2012  * Check whether a reply is allowed, remove BusPendingReply
2013  * if so, return TRUE if so.
2014  */
2015 dbus_bool_t
2016 bus_connections_check_reply (BusConnections *connections,
2017                              BusTransaction *transaction,
2018                              DBusConnection *sending_reply,
2019                              DBusConnection *receiving_reply,
2020                              DBusMessage    *reply,
2021                              DBusError      *error)
2022 {
2023   CheckPendingReplyData *cprd;
2024   DBusList *link;
2025   dbus_uint32_t reply_serial;
2026
2027   _dbus_assert (sending_reply != NULL);
2028   _dbus_assert (receiving_reply != NULL);
2029
2030   reply_serial = dbus_message_get_reply_serial (reply);
2031
2032   link = bus_expire_list_get_first_link (connections->pending_replies);
2033   while (link != NULL)
2034     {
2035       BusPendingReply *pending = link->data;
2036
2037       if (pending->reply_serial == reply_serial &&
2038           pending->will_get_reply == receiving_reply &&
2039           pending->will_send_reply == sending_reply)
2040         {
2041           _dbus_verbose ("Found pending reply with serial %u\n", reply_serial);
2042           break;
2043         }
2044
2045       link = bus_expire_list_get_next_link (connections->pending_replies,
2046                                             link);
2047     }
2048
2049   if (link == NULL)
2050     {
2051       _dbus_verbose ("No pending reply expected\n");
2052
2053       return FALSE;
2054     }
2055
2056   cprd = dbus_new0 (CheckPendingReplyData, 1);
2057   if (cprd == NULL)
2058     {
2059       BUS_SET_OOM (error);
2060       return FALSE;
2061     }
2062
2063   if (!bus_transaction_add_cancel_hook (transaction,
2064                                         cancel_check_pending_reply,
2065                                         cprd,
2066                                         check_pending_reply_data_free))
2067     {
2068       BUS_SET_OOM (error);
2069       dbus_free (cprd);
2070       return FALSE;
2071     }
2072
2073   cprd->link = link;
2074   cprd->connections = connections;
2075
2076   bus_expire_list_unlink (connections->pending_replies,
2077                           link);
2078
2079   _dbus_assert (!bus_expire_list_contains_item (connections->pending_replies, link->data));
2080
2081   return TRUE;
2082 }
2083
2084 /*
2085  * Transactions
2086  *
2087  * Note that this is fairly fragile; in particular, don't try to use
2088  * one transaction across any main loop iterations.
2089  */
2090
2091 typedef struct
2092 {
2093   BusTransaction *transaction;
2094   DBusMessage    *message;
2095   DBusPreallocatedSend *preallocated;
2096 } MessageToSend;
2097
2098 typedef struct
2099 {
2100   BusTransactionCancelFunction cancel_function;
2101   DBusFreeFunction free_data_function;
2102   void *data;
2103 } CancelHook;
2104
2105 struct BusTransaction
2106 {
2107   DBusList *connections;
2108   BusContext *context;
2109   DBusList *cancel_hooks;
2110 };
2111
2112 static void
2113 message_to_send_free (DBusConnection *connection,
2114                       MessageToSend  *to_send)
2115 {
2116   if (to_send->message)
2117     dbus_message_unref (to_send->message);
2118
2119   if (to_send->preallocated)
2120     dbus_connection_free_preallocated_send (connection, to_send->preallocated);
2121
2122   dbus_free (to_send);
2123 }
2124
2125 static void
2126 cancel_hook_cancel (void *element,
2127                     void *data)
2128 {
2129   CancelHook *ch = element;
2130
2131   _dbus_verbose ("Running transaction cancel hook\n");
2132
2133   if (ch->cancel_function)
2134     (* ch->cancel_function) (ch->data);
2135 }
2136
2137 static void
2138 cancel_hook_free (void *element,
2139                   void *data)
2140 {
2141   CancelHook *ch = element;
2142
2143   if (ch->free_data_function)
2144     (* ch->free_data_function) (ch->data);
2145
2146   dbus_free (ch);
2147 }
2148
2149 static void
2150 free_cancel_hooks (BusTransaction *transaction)
2151 {
2152   _dbus_list_foreach (&transaction->cancel_hooks,
2153                       cancel_hook_free, NULL);
2154
2155   _dbus_list_clear (&transaction->cancel_hooks);
2156 }
2157
2158 BusTransaction*
2159 bus_transaction_new (BusContext *context)
2160 {
2161   BusTransaction *transaction;
2162
2163   transaction = dbus_new0 (BusTransaction, 1);
2164   if (transaction == NULL)
2165     return NULL;
2166
2167   transaction->context = context;
2168
2169   return transaction;
2170 }
2171
2172 BusContext*
2173 bus_transaction_get_context (BusTransaction  *transaction)
2174 {
2175   return transaction->context;
2176 }
2177
2178 /**
2179  * Reserve enough memory to capture the given message if the
2180  * transaction goes through.
2181  */
2182 dbus_bool_t
2183 bus_transaction_capture (BusTransaction *transaction,
2184                          DBusConnection *sender,
2185                          DBusConnection *addressed_recipient,
2186                          DBusMessage    *message)
2187 {
2188   BusConnections *connections;
2189   BusMatchmaker *mm;
2190   DBusList *link;
2191   DBusList *recipients = NULL;
2192   dbus_bool_t ret = FALSE;
2193
2194   connections = bus_context_get_connections (transaction->context);
2195
2196   /* shortcut: don't compose the message unless someone wants it */
2197   if (connections->monitors == NULL)
2198     return TRUE;
2199
2200   mm = connections->monitor_matchmaker;
2201   /* This is non-null if there has ever been a monitor - we don't GC it.
2202    * There's little point, since there is up to 1 per process. */
2203   _dbus_assert (mm != NULL);
2204
2205   if (!bus_matchmaker_get_recipients (mm, connections, sender,
2206         addressed_recipient, message, &recipients))
2207     goto out;
2208
2209   for (link = _dbus_list_get_first_link (&recipients);
2210       link != NULL;
2211       link = _dbus_list_get_next_link (&recipients, link))
2212     {
2213       DBusConnection *recipient = link->data;
2214
2215       if (!bus_transaction_send (transaction, recipient, message))
2216         goto out;
2217     }
2218
2219   ret = TRUE;
2220
2221 out:
2222   _dbus_list_clear (&recipients);
2223   return ret;
2224 }
2225
2226 dbus_bool_t
2227 bus_transaction_capture_error_reply (BusTransaction  *transaction,
2228                                      DBusConnection  *addressed_recipient,
2229                                      const DBusError *error,
2230                                      DBusMessage     *in_reply_to)
2231 {
2232   BusConnections *connections;
2233   DBusMessage *reply;
2234   dbus_bool_t ret = FALSE;
2235
2236   _dbus_assert (error != NULL);
2237   _DBUS_ASSERT_ERROR_IS_SET (error);
2238
2239   connections = bus_context_get_connections (transaction->context);
2240
2241   /* shortcut: don't compose the message unless someone wants it */
2242   if (connections->monitors == NULL)
2243     return TRUE;
2244
2245   reply = dbus_message_new_error (in_reply_to,
2246                                   error->name,
2247                                   error->message);
2248
2249   if (reply == NULL)
2250     return FALSE;
2251
2252   if (!dbus_message_set_sender (reply, DBUS_SERVICE_DBUS))
2253     goto out;
2254
2255   ret = bus_transaction_capture (transaction, NULL, addressed_recipient, reply);
2256
2257 out:
2258   dbus_message_unref (reply);
2259   return ret;
2260 }
2261
2262 dbus_bool_t
2263 bus_transaction_send_from_driver (BusTransaction *transaction,
2264                                   DBusConnection *connection,
2265                                   DBusMessage    *message)
2266 {
2267   DBusError error = DBUS_ERROR_INIT;
2268
2269   /* We have to set the sender to the driver, and have
2270    * to check security policy since it was not done in
2271    * dispatch.c
2272    */
2273   _dbus_verbose ("Sending %s %s %s from driver\n",
2274                  dbus_message_get_interface (message) ?
2275                  dbus_message_get_interface (message) : "(no interface)",
2276                  dbus_message_get_member (message) ?
2277                  dbus_message_get_member (message) : "(no member)",
2278                  dbus_message_get_error_name (message) ?
2279                  dbus_message_get_error_name (message) : "(no error name)");
2280
2281   if (!dbus_message_set_sender (message, DBUS_SERVICE_DBUS))
2282     return FALSE;
2283
2284   if (bus_connection_is_active (connection))
2285     {
2286       if (!dbus_message_set_destination (message,
2287                                          bus_connection_get_name (connection)))
2288         return FALSE;
2289     }
2290
2291   /* bus driver never wants a reply */
2292   dbus_message_set_no_reply (message, TRUE);
2293
2294   /* Capture it for monitors, even if the real recipient's receive policy
2295    * does not allow it to receive this message from us (which would be odd).
2296    */
2297   if (!bus_transaction_capture (transaction, NULL, connection, message))
2298     return FALSE;
2299
2300   /* If security policy doesn't allow the message, we would silently
2301    * eat it; the driver doesn't care about getting a reply. However,
2302    * if we're actively capturing messages, it's nice to log that we
2303    * tried to send it and did not allow ourselves to do so.
2304    */
2305   if (!bus_context_check_security_policy (bus_transaction_get_context (transaction),
2306                                           transaction,
2307                                           NULL, connection, connection, message, &error))
2308     {
2309       if (!bus_transaction_capture_error_reply (transaction, connection,
2310                                                 &error, message))
2311         {
2312           bus_context_log (transaction->context, DBUS_SYSTEM_LOG_WARNING,
2313                            "message from dbus-daemon rejected but not enough "
2314                            "memory to capture it");
2315         }
2316
2317       /* This is not fatal to the transaction so silently eat the disallowed
2318        * message (see reasoning above) */
2319       dbus_error_free (&error);
2320       return TRUE;
2321     }
2322
2323   return bus_transaction_send (transaction, connection, message);
2324 }
2325
2326 dbus_bool_t
2327 bus_transaction_send (BusTransaction *transaction,
2328                       DBusConnection *connection,
2329                       DBusMessage    *message)
2330 {
2331   MessageToSend *to_send;
2332   BusConnectionData *d;
2333   DBusList *link;
2334
2335   _dbus_verbose ("  trying to add %s interface=%s member=%s error=%s to transaction%s\n",
2336                  dbus_message_get_type (message) == DBUS_MESSAGE_TYPE_ERROR ? "error" :
2337                  dbus_message_get_reply_serial (message) != 0 ? "reply" :
2338                  "message",
2339                  dbus_message_get_interface (message) ?
2340                  dbus_message_get_interface (message) : "(unset)",
2341                  dbus_message_get_member (message) ?
2342                  dbus_message_get_member (message) : "(unset)",
2343                  dbus_message_get_error_name (message) ?
2344                  dbus_message_get_error_name (message) : "(unset)",
2345                  dbus_connection_get_is_connected (connection) ?
2346                  "" : " (disconnected)");
2347
2348   _dbus_assert (dbus_message_get_sender (message) != NULL);
2349
2350   if (!dbus_connection_get_is_connected (connection))
2351     return TRUE; /* silently ignore disconnected connections */
2352
2353   d = BUS_CONNECTION_DATA (connection);
2354   _dbus_assert (d != NULL);
2355
2356   to_send = dbus_new (MessageToSend, 1);
2357   if (to_send == NULL)
2358     {
2359       return FALSE;
2360     }
2361
2362   to_send->preallocated = dbus_connection_preallocate_send (connection);
2363   if (to_send->preallocated == NULL)
2364     {
2365       dbus_free (to_send);
2366       return FALSE;
2367     }
2368
2369   dbus_message_ref (message);
2370   to_send->message = message;
2371   to_send->transaction = transaction;
2372
2373   _dbus_verbose ("about to prepend message\n");
2374
2375   if (!_dbus_list_prepend (&d->transaction_messages, to_send))
2376     {
2377       message_to_send_free (connection, to_send);
2378       return FALSE;
2379     }
2380
2381   _dbus_verbose ("prepended message\n");
2382
2383   /* See if we already had this connection in the list
2384    * for this transaction. If we have a pending message,
2385    * then we should already be in transaction->connections
2386    */
2387   link = _dbus_list_get_first_link (&d->transaction_messages);
2388   _dbus_assert (link->data == to_send);
2389   link = _dbus_list_get_next_link (&d->transaction_messages, link);
2390   while (link != NULL)
2391     {
2392       MessageToSend *m = link->data;
2393       DBusList *next = _dbus_list_get_next_link (&d->transaction_messages, link);
2394
2395       if (m->transaction == transaction)
2396         break;
2397
2398       link = next;
2399     }
2400
2401   if (link == NULL)
2402     {
2403       if (!_dbus_list_prepend (&transaction->connections, connection))
2404         {
2405           _dbus_list_remove (&d->transaction_messages, to_send);
2406           message_to_send_free (connection, to_send);
2407           return FALSE;
2408         }
2409     }
2410
2411   return TRUE;
2412 }
2413
2414 static void
2415 transaction_free (BusTransaction *transaction)
2416 {
2417   _dbus_assert (transaction->connections == NULL);
2418
2419   free_cancel_hooks (transaction);
2420
2421   dbus_free (transaction);
2422 }
2423
2424 static void
2425 connection_cancel_transaction (DBusConnection *connection,
2426                                BusTransaction *transaction)
2427 {
2428   DBusList *link;
2429   BusConnectionData *d;
2430
2431   d = BUS_CONNECTION_DATA (connection);
2432   _dbus_assert (d != NULL);
2433
2434   link = _dbus_list_get_first_link (&d->transaction_messages);
2435   while (link != NULL)
2436     {
2437       MessageToSend *m = link->data;
2438       DBusList *next = _dbus_list_get_next_link (&d->transaction_messages, link);
2439
2440       if (m->transaction == transaction)
2441         {
2442           _dbus_list_remove_link (&d->transaction_messages,
2443                                   link);
2444
2445           message_to_send_free (connection, m);
2446         }
2447
2448       link = next;
2449     }
2450 }
2451
2452 void
2453 bus_transaction_cancel_and_free (BusTransaction *transaction)
2454 {
2455   DBusConnection *connection;
2456
2457   _dbus_verbose ("TRANSACTION: cancelled\n");
2458
2459   while ((connection = _dbus_list_pop_first (&transaction->connections)))
2460     connection_cancel_transaction (connection, transaction);
2461
2462   _dbus_list_foreach (&transaction->cancel_hooks,
2463                       cancel_hook_cancel, NULL);
2464
2465   transaction_free (transaction);
2466 }
2467
2468 static void
2469 connection_execute_transaction (DBusConnection *connection,
2470                                 BusTransaction *transaction)
2471 {
2472   DBusList *link;
2473   BusConnectionData *d;
2474
2475   d = BUS_CONNECTION_DATA (connection);
2476   _dbus_assert (d != NULL);
2477
2478   /* Send the queue in order (FIFO) */
2479   link = _dbus_list_get_last_link (&d->transaction_messages);
2480   while (link != NULL)
2481     {
2482       MessageToSend *m = link->data;
2483       DBusList *prev = _dbus_list_get_prev_link (&d->transaction_messages, link);
2484
2485       if (m->transaction == transaction)
2486         {
2487           _dbus_list_remove_link (&d->transaction_messages,
2488                                   link);
2489
2490           _dbus_assert (dbus_message_get_sender (m->message) != NULL);
2491
2492           dbus_connection_send_preallocated (connection,
2493                                              m->preallocated,
2494                                              m->message,
2495                                              NULL);
2496
2497           m->preallocated = NULL; /* so we don't double-free it */
2498
2499           message_to_send_free (connection, m);
2500         }
2501
2502       link = prev;
2503     }
2504 }
2505
2506 void
2507 bus_transaction_execute_and_free (BusTransaction *transaction)
2508 {
2509   /* For each connection in transaction->connections
2510    * send the messages
2511    */
2512   DBusConnection *connection;
2513
2514   _dbus_verbose ("TRANSACTION: executing\n");
2515
2516   while ((connection = _dbus_list_pop_first (&transaction->connections)))
2517     connection_execute_transaction (connection, transaction);
2518
2519   transaction_free (transaction);
2520 }
2521
2522 static void
2523 bus_connection_remove_transactions (DBusConnection *connection)
2524 {
2525   MessageToSend *to_send;
2526   BusConnectionData *d;
2527
2528   d = BUS_CONNECTION_DATA (connection);
2529   _dbus_assert (d != NULL);
2530
2531   while ((to_send = _dbus_list_get_first (&d->transaction_messages)))
2532     {
2533       /* only has an effect for the first MessageToSend listing this transaction */
2534       _dbus_list_remove (&to_send->transaction->connections,
2535                          connection);
2536
2537       _dbus_list_remove (&d->transaction_messages, to_send);
2538       message_to_send_free (connection, to_send);
2539     }
2540 }
2541
2542 /**
2543  * Converts the DBusError to a message reply
2544  */
2545 dbus_bool_t
2546 bus_transaction_send_error_reply (BusTransaction  *transaction,
2547                                   DBusConnection  *connection,
2548                                   const DBusError *error,
2549                                   DBusMessage     *in_reply_to)
2550 {
2551   DBusMessage *reply;
2552
2553   _dbus_assert (error != NULL);
2554   _DBUS_ASSERT_ERROR_IS_SET (error);
2555
2556   _dbus_verbose ("Sending error reply %s \"%s\"\n",
2557                  error->name, error->message);
2558
2559   reply = dbus_message_new_error (in_reply_to,
2560                                   error->name,
2561                                   error->message);
2562   if (reply == NULL)
2563     return FALSE;
2564
2565   if (!bus_transaction_send_from_driver (transaction, connection, reply))
2566     {
2567       dbus_message_unref (reply);
2568       return FALSE;
2569     }
2570
2571   dbus_message_unref (reply);
2572
2573   return TRUE;
2574 }
2575
2576 dbus_bool_t
2577 bus_transaction_add_cancel_hook (BusTransaction               *transaction,
2578                                  BusTransactionCancelFunction  cancel_function,
2579                                  void                         *data,
2580                                  DBusFreeFunction              free_data_function)
2581 {
2582   CancelHook *ch;
2583
2584   ch = dbus_new (CancelHook, 1);
2585   if (ch == NULL)
2586     return FALSE;
2587
2588   _dbus_verbose ("     adding cancel hook function = %p data = %p\n",
2589                  cancel_function, data);
2590
2591   ch->cancel_function = cancel_function;
2592   ch->data = data;
2593   ch->free_data_function = free_data_function;
2594
2595   /* It's important that the hooks get run in reverse order that they
2596    * were added
2597    */
2598   if (!_dbus_list_prepend (&transaction->cancel_hooks, ch))
2599     {
2600       dbus_free (ch);
2601       return FALSE;
2602     }
2603
2604   return TRUE;
2605 }
2606
2607 int
2608 bus_connections_get_n_active (BusConnections *connections)
2609 {
2610   return connections->n_completed;
2611 }
2612
2613 int
2614 bus_connections_get_n_incomplete (BusConnections *connections)
2615 {
2616   return connections->n_incomplete;
2617 }
2618
2619 #ifdef DBUS_ENABLE_STATS
2620 int
2621 bus_connections_get_total_match_rules (BusConnections *connections)
2622 {
2623   return connections->total_match_rules;
2624 }
2625
2626 int
2627 bus_connections_get_peak_match_rules (BusConnections *connections)
2628 {
2629   return connections->peak_match_rules;
2630 }
2631
2632 int
2633 bus_connections_get_peak_match_rules_per_conn (BusConnections *connections)
2634 {
2635   return connections->peak_match_rules_per_conn;
2636 }
2637
2638 int
2639 bus_connections_get_total_bus_names (BusConnections *connections)
2640 {
2641   return connections->total_bus_names;
2642 }
2643
2644 int
2645 bus_connections_get_peak_bus_names (BusConnections *connections)
2646 {
2647   return connections->peak_bus_names;
2648 }
2649
2650 int
2651 bus_connections_get_peak_bus_names_per_conn (BusConnections *connections)
2652 {
2653   return connections->peak_bus_names_per_conn;
2654 }
2655
2656 int
2657 bus_connection_get_peak_match_rules (DBusConnection *connection)
2658 {
2659   BusConnectionData *d;
2660
2661   d = BUS_CONNECTION_DATA (connection);
2662   _dbus_assert(d != NULL);
2663
2664   return d->peak_match_rules;
2665 }
2666
2667 int
2668 bus_connection_get_peak_bus_names (DBusConnection *connection)
2669 {
2670   BusConnectionData *d;
2671
2672   d = BUS_CONNECTION_DATA (connection);
2673   _dbus_assert(d != NULL);
2674
2675   return d->peak_bus_names;
2676 }
2677 #endif /* DBUS_ENABLE_STATS */
2678
2679 dbus_bool_t
2680 bus_connection_is_monitor (DBusConnection *connection)
2681 {
2682   BusConnectionData *d;
2683
2684   d = BUS_CONNECTION_DATA (connection);
2685   _dbus_assert(d != NULL);
2686
2687   return d->link_in_monitors != NULL;
2688 }
2689
2690 static dbus_bool_t
2691 bcd_add_monitor_rules (BusConnectionData  *d,
2692                        DBusConnection     *connection,
2693                        DBusList          **rules)
2694 {
2695   BusMatchmaker *mm = d->connections->monitor_matchmaker;
2696   DBusList *iter;
2697
2698   if (mm == NULL)
2699     {
2700       mm = bus_matchmaker_new ();
2701
2702       if (mm == NULL)
2703         return FALSE;
2704
2705       d->connections->monitor_matchmaker = mm;
2706     }
2707
2708   for (iter = _dbus_list_get_first_link (rules);
2709       iter != NULL;
2710       iter = _dbus_list_get_next_link (rules, iter))
2711     {
2712       if (!bus_matchmaker_add_rule (mm, iter->data))
2713         {
2714           bus_matchmaker_disconnected (mm, connection);
2715           return FALSE;
2716         }
2717     }
2718
2719   return TRUE;
2720 }
2721
2722 static void
2723 bcd_drop_monitor_rules (BusConnectionData *d,
2724                         DBusConnection *connection)
2725 {
2726   BusMatchmaker *mm = d->connections->monitor_matchmaker;
2727
2728   if (mm != NULL)
2729     bus_matchmaker_disconnected (mm, connection);
2730 }
2731
2732 dbus_bool_t
2733 bus_connection_be_monitor (DBusConnection  *connection,
2734                            BusTransaction  *transaction,
2735                            DBusList       **rules,
2736                            DBusError       *error)
2737 {
2738   BusConnectionData *d;
2739   DBusList *link;
2740   DBusList *tmp;
2741   DBusList *iter;
2742
2743   d = BUS_CONNECTION_DATA (connection);
2744   _dbus_assert (d != NULL);
2745
2746   link = _dbus_list_alloc_link (connection);
2747
2748   if (link == NULL)
2749     {
2750       BUS_SET_OOM (error);
2751       return FALSE;
2752     }
2753
2754   if (!bcd_add_monitor_rules (d, connection, rules))
2755     {
2756       _dbus_list_free_link (link);
2757       BUS_SET_OOM (error);
2758       return FALSE;
2759     }
2760
2761   /* release all its names */
2762   if (!_dbus_list_copy (&d->services_owned, &tmp))
2763     {
2764       bcd_drop_monitor_rules (d, connection);
2765       _dbus_list_free_link (link);
2766       BUS_SET_OOM (error);
2767       return FALSE;
2768     }
2769
2770   for (iter = _dbus_list_get_first_link (&tmp);
2771       iter != NULL;
2772       iter = _dbus_list_get_next_link (&tmp, iter))
2773     {
2774       BusService *service = iter->data;
2775
2776       /* This call is transactional: if there isn't enough memory to
2777        * do everything, then the service gets all its names back when
2778        * the transaction is cancelled due to OOM. */
2779       if (!bus_service_remove_owner (service, connection, transaction, error))
2780         {
2781           bcd_drop_monitor_rules (d, connection);
2782           _dbus_list_free_link (link);
2783           _dbus_list_clear (&tmp);
2784           return FALSE;
2785         }
2786     }
2787
2788   /* We have now done everything that can fail, so there is no problem
2789    * with doing the irrevocable stuff. */
2790
2791   _dbus_list_clear (&tmp);
2792
2793   bus_context_log (transaction->context, DBUS_SYSTEM_LOG_INFO,
2794                    "Connection %s (%s) became a monitor.", d->name,
2795                    d->cached_loginfo_string);
2796
2797   if (d->n_match_rules > 0)
2798     {
2799       BusMatchmaker *mm;
2800
2801       mm = bus_context_get_matchmaker (d->connections->context);
2802       bus_matchmaker_disconnected (mm, connection);
2803     }
2804
2805   /* flag it as a monitor */
2806   d->link_in_monitors = link;
2807   _dbus_list_append_link (&d->connections->monitors, link);
2808
2809   /* it isn't allowed to reply, and it is no longer relevant whether it
2810    * receives replies */
2811   bus_connection_drop_pending_replies (d->connections, connection);
2812
2813   return TRUE;
2814 }